Foldable, lockable control surface and method of using same

ABSTRACT

A foldable, lockable control surface includes an inner control surface member and an outer control surface member hingedly attached along a hinge line to the inner control surface member. The control surface further includes a biasing assembly disposed on the hinge line, the outer control surface being operably associated with the inner control surface member and the outer control surface member and a locking mechanism operably associated with the outer control surface member. An apparatus includes a foldable, lockable control surface having a control surface actuation shaft extending therefrom and a control surface actuator having a control surface actuator output port in which the control surface actuation shaft is received. The apparatus further includes means for clocking the control surface actuation shaft in the control surface actuator output port.

The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of contract number DAAH01-03-C-0164 awarded by the United States Army.

BACKGROUND

1. Field of the Invention

The present invention relates to control surfaces for an airborne or waterborne vehicle. In particular, the present invention relates to a foldable, lockable control surface for an airborne or waterborne vehicle and a method of using the control surface.

2. Description of Related Art

Airborne and waterborne vehicles are often used to deliver a payload to a target location or to carry the payload over a desired area. For example, rockets, missiles, torpedoes, drones, projectiles, and other such vehicles may be used in combat situations to deliver explosive warheads, kinetic energy penetrators, or other payloads to destroy or disable the target. Surveillance vehicles may carry a payload designed to sense certain conditions surrounding the vehicle, such as objects on the ground or weather conditions.

Such vehicles may include a plurality of control surfaces for controlling their trajectories during flight. As the vehicle travels through the air or water, the attitudes of the control surfaces are adjusted to change the flight path of the vehicle. In the interest of space economy, however, it is generally desirable for the vehicle to be stored with its control surfaces folded prior to its deployment. For example, a projectile's control surfaces may be folded so that the diameter of the firing tube from which the projectile is deployed may be smaller than otherwise required. Once deployed, aerodynamic forces exerted on the control surfaces necessitate that the control surfaces are locked into their deployed, unfolded positions. Accordingly, a mechanism is needed to hold each of the control surfaces in the unfolded, deployed configuration.

Conventional control surfaces may be retained in their unfolded, deployed configurations by some type of mechanism external to the vehicle, such as a wire, a band, or a hook. In many cases, the mechanism is released from the vehicle's body after the control surfaces are unfolded, thus presenting a potential debris problem for the surrounding environment. Further, some launch tubes for projectiles employ additional control surface restraint devices that are ejected after the projectile leaves the launch tube. These restraint devices also pose problems for the surrounding environment, as they may impact the launch platform or other surrounding equipment. Still other mechanisms used to unfold control surfaces employ external power sources, pyrotechnics, or chemical activation for deployment. Such mechanisms are complex and can present hazardous situations if improperly activated.

Mechanisms used to retain control surfaces in their unfolded, deployed configurations also use external power sources, pyrotechnics, or chemical activation for actuating the retention mechanisms, with similar problems as noted above. Moreover, dimensions of the mechanical locking members used to retain the control surfaces in their unfolded, deployed configurations are typically closely matched with those of their mating structures. Generally, such close dimensional tolerances require expensive, time consuming machining or other manufacturing processes.

While there are many foldable control surfaces well known in the art, considerable room for improvement remains.

SUMMARY OF THE INVENTION

There is a need for a foldable, lockable control surface for an airborne or waterborne vehicle.

Therefore, it is an object of the present invention to provide a foldable, lockable control surface for an airborne or waterborne vehicle.

In one aspect, the present invention provides a foldable, lockable control surface. The control surface includes an inner control surface member and an outer control surface member hingedly attached along a hinge line to the inner control surface member. The control surface further includes a biasing assembly disposed on the hinge line, the biasing assembly being operably associated with the inner control surface member and the outer control surface member, and a locking mechanism operably associated with the outer control surface member.

In another aspect, the present invention provides a foldable, lockable control surface. The control surface includes an inner control surface member including a forward hinge lug, a first intermediate hinge lug, a second intermediate hinge lug, and an aft hinge lug, the inner control surface member defining a recess and a passageway intersecting the recess. An outer control surface member includes a forward hinge lug, an intermediate hinge lug, and an aft hinge lug, the intermediate hinge lug defining a slot, the hinge lugs of the inner control surface member and the hinge lugs of the outer control surface member defining a hinge line.

A forward biasing assembly is disposed on the hinge line between the forward hinge lug of the outer control surface member and the first intermediate hinge lug of the inner control surface member. An aft biasing assembly is disposed on the hinge line between the second intermediate hinge lug of the inner control surface member and the aft hinge lug of the inner control surface member. A forward hinge pin is attached to the forward hinge lug of the inner control surface member and attached to the forward biasing assembly, such that the forward hinge pin extends through the forward hinge lug of the outer control surface member. An intermediate hinge pin is attached to the forward biasing assembly, to the intermediate hinge lug of the outer control surface member, and to the aft biasing assembly, such that the intermediate hinge pin extends through the first intermediate hinge lug of the inner control surface member, through the intermediate hinge lug of the outer control surface member, and through the second intermediate hinge lug of the inner control surface member. An aft hinge pin is attached to the aft biasing assembly and is attached to the aft hinge lug of the inner control surface member, such that the aft hinge pin extends into the aft hinge lug of the outer control surface member.

A wedge is disposed in the recess of the inner control surface member. A wedge biasing element is disposed in the recess between the wedge and the inner control surface member, such that the wedge biasing element urges the wedge into the slot of the intermediate hinge lug of the outer control surface member when the slot and the recess are substantially aligned. A retainer stop and a retainer guide, which is attached to the retainer stop, are disposed in the passageway. A retainer guide biasing element is disposed in the passageway between the retainer guide and the inner control surface member, such that the retainer guide biasing element urges the retainer stop into the recess when the wedge is disposed in the slot.

In yet another aspect of the present invention, an apparatus is provided. The apparatus includes a foldable, lockable control surface having a control surface actuation shaft extending therefrom and a control surface actuator having a control surface actuator output port in which the control surface actuation shaft is received. The apparatus further includes means for clocking the control surface actuation shaft in the control surface actuator output port.

In yet another aspect, the present invention provides a method of locking a first member with respect to a second member. The method includes providing the first member hingedly attached to the second member and hingedly moving the first member with a biasing mechanism until a slot of the first member is substantially aligned with a recess of the second member. The method further includes moving a wedge, disposed in the recess, into the slot and moving a retainer stop into the recess to inhibit the wedge from withdrawing from the slot.

The present invention provides significant advantages, including: (1) aerodynamic loads exerted on the outer control surface member are efficiently transmitted to the inner control surface member via the hinge attachment; (2) the locking mechanism of the present invention limits flutter in the outer control surface member during flight; and (3) the locking mechanism of the present invention requires no externally-provided motive force to operate.

Additional objectives, features and advantages will be apparent in the written description which follows.

DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the invention are set forth in the appended claims. However, the invention itself, as well as, a preferred mode of use, and further objectives and advantages thereof, will best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is perspective view of an illustrative embodiment of a foldable, lockable control surface according to the present invention in an unfolded, deployed configuration;

FIG. 2 is a perspective view of the control surface of FIG. 1 in a folded, stowed configuration;

FIG. 3 is an exploded, perspective view of the control surface of FIG. 1;

FIG. 4 is a perspective view of a biasing assembly of the control surface of FIG. 1;

FIG. 5 is an exploded, perspective view of the biasing assembly of FIG. 4;

FIGS. 6-8 are cross-sectional views of the control surface of FIG. 1 taken along the line 6-6 of FIG. 1 illustrating particular details and one particular operation of the control surface;

FIG. 9A is a stylized, side elevational view depicting particular aspects of an illustrative embodiment of a locking wedge and slot of the control surface of FIG. 1;

FIG. 9B is a stylized, side elevational view depicting particular aspects of an alternative, illustrative embodiment of a locking wedge and slot of the control surface of FIG. 1;

FIG. 10 is a cross-sectional view of the control surface of FIG. 1 taken along the line 10-10 of FIG. 1, additionally showing a wedge retraction tool;

FIG. 11 is a cross-sectional view of the control surface of FIG. 2, taken along the line 11-11 of FIG. 2;

FIG. 12 is a perspective view of an illustrative embodiment of a control surface actuator of the present invention, to which the control surface of FIG. 1 may be operably associated; and

FIG. 13 is a stylized, side, elevational view of a vehicle according to the present invention incorporating a plurality of the control surfaces of FIG. 1 and a corresponding plurality of control surface actuators of FIG. 12.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

The present invention represents a foldable, lockable control surface for an airborne or waterborne vehicle. Such vehicles include, but are not limited to, missiles, rockets, drones, projectiles, torpedoes, and the like, which are adapted to travel through a medium, whether substantially comprising air or water. A plurality of the foldable, lockable control surfaces of the present invention is operably associated with an airborne or waterborne vehicle to affect a spatial attitude, and thus a trajectory, of the vehicle as the vehicle travels through the medium. In other words, one or more actuators of the vehicle move one or more of the plurality of foldable, lockable control surfaces to affect the roll, pitch, and/or yaw of the vehicle as the vehicle travels through the medium.

Vehicles are typically stored in containers or canisters to enhance vehicle portability, for vehicle protection during transportation and storage, and/or for use during deployment of the vehicle. Generally, it is desirable for the overall size and, in particular, the cross-sectional area, of such a canister to be as small as possible to limit the volume of space required to store and present the vehicle for deployment. Moreover, the size of such a canister is determined based upon the configuration of equipment used to transport and/or deploy the vehicle. The foldable, lockable control surface of the present invention allows larger and/or longer control surfaces to be operably associated with a vehicle, while still being housed within a smaller canister prior to deployment.

FIGS. 1-3 depict an illustrative embodiment of a foldable, lockable control surface 101 according to the present invention. FIG. 1 provides a perspective view of control surface 101 in a deployed or unfolded configuration, while FIG. 2 provides a perspective view of control surface 101 in a stowed or folded configuration. FIG. 3 provides an exploded, perspective view of control surface 101. Generally, control surface 101 comprises an outer control surface member 103 hingedly attached to an inner control surface member 105. In the illustrated embodiment, outer control surface member 103 comprises a forward hinge lug 107, an intermediate hinge lug 109, and an aft hinge lug 111, all extending from an airfoil portion 113. Inner control surface member 105 comprises a forward hinge lug 115, a first intermediate hinge lug 117, a second intermediate hinge lug 119, and an aft hinge lug 121, all extending from an airfoil portion 123.

A forward biasing assembly 125 is disposed between forward hinge lug 107 of outer control surface member 103 and first intermediate hinge lug 117 of inner control surface member 105. An aft biasing assembly 127 is disposed between second intermediate hinge lug 119 of inner control surface member 105 and aft hinge lug 121 of inner control surface member 105. Note that the scope of the present invention encompasses embodiments having only one biasing assembly 125, 127 or more than two biasing assemblies 125, 127. A forward hinge pin 129 extends through forward hinge lug 107 of outer control surface member 103, between forward hinge lug 115 of inner control surface member 105 and forward biasing assembly 125. An intermediate hinge pin 131 extends between forward biasing assembly 125 and aft biasing assembly 127, through first intermediate hinge lug 117 of inner control surface member 105, intermediate hinge lug 109 of outer control surface member 103, and second intermediate hinge lug 119 of inner control surface member 105. An aft hinge pin 133 extends through aft lug 121 of inner control surface member 103, between aft lug 111 of outer control surface member 103 and aft biasing assembly 127. Hinge pins 129, 131, 133 are fixed in position by pins 135 a-135 e, which extend between biasing assemblies 125, 127 and hinge pins 129, 131, 133. Thus, outer control surface member 103 is hingedly attached to and foldable with respect to inner control surface member 105, with biasing assemblies 125, 127 being disposed along a hinge axis 209 of control surface 101. Note that, when unfolded, outer control surface member 103 abuts stopping means, e.g., location tabs 207.

FIG. 4 provides a perspective view of one particular embodiment of biasing assemblies 125, 127. FIG. 5 illustrates an exploded, perspective view of the biasing assembly embodiment of FIG. 4. In the illustrated embodiment, biasing assemblies 125, 127 comprise a torsion spring 137 disposed within a tube 139. Covers 141, 143 enclose open ends of tube 139. A tab 145 extends from each of covers 141, 143. Ends of torsion spring 137 are disposed against tabs 145 such that, when torsion spring 137 is rotated with respect to covers 141, 143 (as indicated by arrow 147), torsion spring 137 is preloaded to a pre-deployed, wound configuration. Cover 143 is attached to tube 139, e.g., by dimpling. Cover 141 is fixed with respect to forward hinge lug 115 of inner control surface member 105 or with respect to aft hinge lug 121 of inner control surface member 105 by torsion preload locking pins 136 a, 136 b (best shown in FIG. 3).

Referring again to FIGS. 1-3, control surface 101 further comprises a locking mechanism operably associated with control surface members 103, 105 to lock outer control surface member 103 in its deployed, unfolded position (illustrated in FIG. 1). In the illustrated embodiment, the locking mechanism comprises a wedge 149, one or more wedge biasing elements 151, a retainer guide 153, a retainer guide biasing element 155, and a retainer stop 157. In the illustrated embodiment, the shape of wedge 149 generally corresponds to a frustum of a pyramid (i.e., is generally frusto-pyramidal in shape), as will be discussed in greater detail below.

FIGS. 6-8 depict, in cross-section, particular details and one illustrative embodiment of an operation of the locking mechanism of the present invention. Intermediate hinge lug 109 of outer control surface member 103 defines a slot 159 that receives wedge 149 when outer control surface member 103 is in the unfolded, deployed, locked configuration. Wedge 149 extends from a recess 161 defined by inner control surface member 105. Wedge 149, however, cannot extend into slot 159 when outer control surface member 103 is in the folded, stowed configuration, due to interference with intermediate hinge lug 109 of outer control surface member 103. Wedge biasing elements 151 are disposed between wedge 149 and inner control surface member 105 within recess 161, such that wedge biasing elements 151 urge wedge 149 toward outer control surface member 103 and into slot 159 when slot 159 and recess 161 are substantially aligned to lock outer control surface member 103 in the unfolded, deployed configuration, shown in FIG. 7. In the illustrated embodiment, wedge 149 interfaces slot 159 along a face 160 of slot 159. Moreover, in the illustrated embodiment, wedge biasing elements 151 comprise helical springs.

Referring again to FIG. 6, retainer guide 153 is disposed in a passageway 163 extending through inner control surface member 105. Passageway 163 intersects recess 161, distal to outer control surface member 103. Passageway 163 includes a first counterbore 165 extending from a first side 167 of inner control surface member 105 and a second counterbore 169 extending from a second side 171 of inner control surface member 105. A head 173 of retainer guide 153 is disposed in first counterbore 165. Retainer guide biasing element 155 is also disposed in first counterbore 165, such that retainer guide biasing element 155 is disposed between head 173 of retainer guide 153 and inner control surface member 105 to urge retainer guide 153 in a direction indicated by an arrow 175. In the illustrated embodiment, retainer guide biasing element 155 comprises one or more wave springs but, in other embodiments, may comprise one or more Bellville washers. Retainer guide 153 is threadedly or otherwise engaged with retainer stop 157. When control surface 101 is in an unlocked configuration, retainer stop 157 is disposed in second counterbore 169 and extends outwardly from second counterbore 169. A flange 176 of retainer stop 157 abuts wedge 149 to prevent retainer stop 157 from entering recess 161.

When slot 159 of intermediate hinge lug 109 and recess 161 of inner control surface member 105 are substantially aligned (i.e., when the vehicle has cleared the canister and outer control surface member 103 is urged into the unfolded, deployed configuration by torsion spring 137), wedge 149 is urged into slot 159 by wedge biasing elements 151, as discussed above. Retainer stop 157 no longer abuts wedge 149, which allows retainer stop 157 to be urged into recess 161 by retainer guide biasing element 155. Note that flange 176 of retainer stop 157 now occupies a space within recess 161 previously occupied by a portion of wedge 149, thus preventing wedge 149 from withdrawing from slot 159. Even if wedge 149 is spaced apart from retainer stop 157 when control surface 101 is in the deployed, unfolded configuration, as shown in FIG. 8, retainer stop 157 is so disposed in recess 161 that wedge cannot fully retract from slot 159.

One particular embodiment of wedge 149 and slot 159 is illustrated in FIG. 9A. In the illustrated embodiment, an upper end 177 of wedge 149 includes a chamfer 181 having an angle A₁ that generally corresponding to a taper angle A₂ of slot 159, shown in phantom in FIG. 9A. Thus, when wedge 149 is urged by wedge biasing elements 151 into slot 159, chamfer 181 contacts slot 159 along face 160. Such a configuration limits flutter in outer control surface member 103 during flight.

An embodiment of wedge 149 and slot 159, alternative to that of FIG. 9A, is illustrated in FIG. 9B. Wedge 149 has a thickness T₁ at upper end 177 and a thickness T₂ at a lower end 179. Thickness T₁ is smaller than thickness T₂ and, moreover, is smaller than a cross-sectional dimension D of slot 159, shown in phantom in FIG. 9B. Thickness T₂, however, is greater than cross-sectional dimension D of slot 159. Thus, wedge 149 is urged by wedge biasing elements 151 into slot 159 until a thickness of wedge 149 fills slot 159. Such a configuration limits flutter in outer control surface member 103 during flight resulting from outer control surface 103 not being rigidly locked into position relative to inner control surface member 105. Also, in the illustrated embodiment, upper end 177 of wedge 149 comprises a chamfer 181 to ease insertion of wedge 149 into slot 159. Thus, in at least the embodiments shown in FIGS. 9A and 9B, wedge 149 and slot 159 are, by way of example and illustration, one anti-fluttering means according to the present invention.

It is sometimes desirable, especially during assembly and installation of control surface 101, to configure control surface 101 in the stowed, folded, unlocked configuration after wedge 149 is disposed in slot 159. As shown in FIGS. 10 and 11, wedge 149 can be retracted from slot 159 by moving retainer stop 157 from recess 161 and, then, withdrawing wedge 149 from slot 159. To accomplish this operation, a wedge retraction tool 183 is inserted through a retraction slot 185 defined by inner control surface member 105 into a retraction orifice 187 defined by wedge 149. Retainer stop 157 is moved from recess 161 by urging retainer guide 153, as indicated by an arrow 189. Wedge 149 is, then, withdrawn from slot 159 by urging wedge retraction tool 183 generally in a direction indicated by an arrow 191. Upper control surface member 103 is rotated to a folded, unlocked configuration. Retraction tool 183 is, then, withdrawn from retraction orifice 187. Thus, by way of example and illustration, retraction orifice 187 and retraction tool 183 are one means for unlocking control surface 101 according to the present invention.

Referring again to FIGS. 1-3, close-out plate pins 193 a, 193 b attach close-out plates 195 a, 195 b to inner control surface member 105. A control surface actuation shaft 197 extends from inner control surface member 105 and operably associates control surface 101 with a control surface actuator 199, shown in FIG. 12. Specifically, control surface actuator shaft 197 is received in control surface actuator output port 201. In one embodiment, control surface actuator 199 includes a clocking means for assuring that control surface actuation shaft 197 is inserted at a correct orientation into control surface actuator output port 201. Particularly, as shown in FIG. 12, a pin or knob 213 extends into control surface actuator output port 201. Control surface actuation shaft 197 can only be inserted into control surface actuator output port 201 such that knob 213 is adjacent a flat 215 (shown in FIGS. 1-3) of control surface actuation shaft 197. As shown in FIG. 13, control surface actuator 199 is disposed within a body 203 of a vehicle 205. Control surface actuation shaft 197 of control surface 101 extends through body 203 to control surface actuator 199. Control surface actuator 199 controls an attitude of control surface 101 to affect the roll, pitch, and yaw of vehicle 205.

Note that, while the drawings depict hinge axis 209 of control surface 101 being generally parallel to a longitudinal axis 211 of vehicle 205, the present invention is not so limited. Rather, the scope of the present invention encompasses a control surface having a hinge axis 209 positioned to an orientation other than generally parallel to longitudinal axis 211 of vehicle 205, particularly by control surface actuator 199. Moreover, the scope of the present invention encompasses a control surface that includes more than one independently foldable and unfoldable outer control surface member, such as outer control surface member 103 and/or more than one portion comprising inner control surface member 105.

The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below. It is apparent that an invention with significant advantages has been described and illustrated. Although the present invention is shown in a limited number of forms, it is not limited to just these forms, but is amenable to various changes and modifications without departing from the spirit thereof. 

1. A foldable, lockable control surface, comprising: an inner control surface member; an outer control surface member hingedly attached along a hinge line to the inner control surface member; a biasing assembly disposed on the hinge line, the biasing assembly being operably associated with the inner control surface member and the outer control surface member; and a locking mechanism operably associated with the outer control surface member.
 2. The foldable, lockable control surface, according to claim 1, wherein the biasing assembly comprises: a torsion spring.
 3. The foldable, lockable control surface, according to claim 2, further comprising: a tube having a first end and a second end; a first cover disposed in the first end of the tube, the first cover defining a first tab; and a second cover disposed in the second end of the tube, the second cover defining a second tab, wherein the torsion spring is disposed within the tube and is operably associated with the first cover and the second cover
 4. The foldable, lockable control surface, according to claim 3, wherein: the first cover defines a first tab and the second cover defines a second tab; and the first end abuts the first tab and the second end abuts the second tab, such that the torsion spring is wound when the second cover is rotated with respect to the first cover in a first direction, and the torsion spring is unwound when the second cover is rotated with respect to the first cover in a second direction.
 5. The foldable, lockable control surface, according to claim 1, wherein: the outer control surface member defines a slot; the inner control surface member defines a recess; and the locking mechanism comprises: a wedge disposed in the recess; and a wedge biasing element disposed in the recess between the inner control surface member and the wedge, such that the wedge biasing element urges the wedge into the slot when the slot and the recess are substantially aligned.
 6. The foldable, lockable control surface, according to claim 5, wherein: the inner control surface member further defines a passageway intersecting the recess; and the locking mechanism further comprises: a retainer stop disposed in the passageway; a retainer guide attached to the retainer stop, the retainer guide being disposed in the passageway, such that the retainer stop inhibits the wedge from moving from the slot when the wedge is disposed in the slot; and a retainer guide biasing element operably associated with the retainer guide to urge the retainer guide into the recess.
 7. The foldable, lockable control surface, according to claim 5, wherein the wedge has a chamfer corresponding to a taper of the slot.
 8. The foldable, lockable control surface, according to claim 5, wherein a first thickness of the wedge is smaller than a cross-sectional dimension of the slot and a second thickness of the wedge is greater than the cross-sectional dimension of the slot.
 9. The foldable, lockable control surface, according to claim 5, wherein the inner control surface member defines a retraction slot and the wedge defines a retraction orifice adapted to receive a wedge retraction tool.
 10. The foldable, lockable control surface, according to claim 1, wherein the locking mechanism comprises: a spring-actuated wedge.
 11. The foldable, lockable control surface, according to claim 1, wherein the locking mechanism comprises: anti-fluttering means operably associated with the upper control surface member.
 12. The foldable, lockable control surface, according to claim 1, further comprising: means for unlocking the upper control surface.
 13. A foldable, lockable control surface, comprising: an inner control surface member including a forward hinge lug, a first intermediate hinge lug, a second intermediate hinge lug, and an aft hinge lug, the inner control surface member defining a recess and a passageway intersecting the recess; an outer control surface member including a forward hinge lug, an intermediate hinge lug, and an aft hinge lug, the intermediate hinge lug defining a slot, the hinge lugs of the inner control surface member and the hinge lugs of the outer control surface member defining a hinge line; a forward biasing assembly disposed on the hinge line between the forward hinge lug of the outer control surface member and the first intermediate hinge lug of the inner control surface member; an aft biasing assembly disposed on the hinge line between the second intermediate hinge lug of the inner control surface member and the aft hinge lug of the inner control surface member; a forward hinge pin attached to the forward hinge lug of the inner control surface member and attached to the forward biasing assembly, the forward hinge pin extending through the forward hinge lug of the outer control surface member; an intermediate hinge pin attached to the forward biasing assembly, to the intermediate hinge lug of the outer control surface member, and to the aft biasing assembly, the intermediate hinge pin extending through the first intermediate hinge lug of the inner control surface member, through the intermediate hinge lug of the outer control surface member, and through the second intermediate hinge lug of the inner control surface member; an aft hinge pin attached to the aft biasing assembly and attached to the aft hinge lug of the inner control surface member, the aft hinge pin extending into the aft hinge lug of the outer control surface member; a wedge disposed in the recess of the inner control surface member; a wedge biasing element disposed in the recess between the wedge and the inner control surface member, such that the wedge biasing element urges the wedge into the slot of the intermediate hinge lug of the outer control surface member when the slot and the recess are substantially aligned; a retainer stop disposed in the passageway; a retainer guide disposed in the passageway and attached to the retainer stop; and a retainer guide biasing element disposed in the passageway between the retainer guide and the inner control surface member, such that the retainer guide biasing element urges the retainer stop into the recess when the wedge is disposed in the slot.
 14. An apparatus, comprising: a foldable, lockable control surface having a control surface actuation shaft extending therefrom; a control surface actuator having a control surface actuator output port in which the control surface actuation shaft is received; and means for clocking the control surface actuation shaft in the control surface actuator output port.
 15. The apparatus, according to claim 14, wherein the means for clocking comprises: a flat defined by the control surface actuation shaft; and a knob extending from the control surface actuator into the control surface actuator output port, wherein the flat and the knob interface to properly clock the control surface with respect to the control surface actuator.
 16. A method of folding a first member relative to a second member, comprising: providing the first member hingedly attached to the second member; hingedly moving the first member with a biasing mechanism until a slot of the first member is substantially aligned with a recess of the second member; moving a wedge, disposed in the recess, into the slot; and moving a retainer stop into the recess to inhibit the wedge from withdrawing from the slot.
 17. The method, according to claim 16, wherein the step of hingedly moving the first member further comprises hingedly moving the first member with a torsion spring.
 18. The method, according to claim 16, wherein the step of moving the wedge further comprises urging the wedge into the slot with a wedge biasing element disposed within the recess between the wedge and the second member.
 19. The method, according to claim 16, wherein the wedge interfaces the slot along a face of the slot.
 20. The method, according to claim 16, wherein the step of moving the retainer stop further comprises urging a retainer guide attached to the retainer stop.
 21. The method, according to claim 16, further comprising: inserting a retraction tool through a retraction slot defined by the second member and into a retraction orifice defined by the wedge; moving the retainer stop from the recess; and withdrawing the wedge from the slot with the retraction tool.
 22. The method, according to claim 16, further comprising: hingedly moving the first member until the slot is misaligned with the recess; and removing the retraction tool from the retraction orifice. 